Silver halide photograhic material

Abstract

A silver halide photographic material comprising a support having thereon at least one light-sensitive layer, the photographic material comprising a reduction-sensitized silver halide emulsion containing a compound in which a group adsorptive to silver halide and a specific hydrazine structure are covalently bonded. The silver halide photographic material exhibits high sensitivity and improved fog characteristics and improved preservation stability.

Claims

1. A silver halide photographic material comprising a support having thereon at least one light-sensitive layer, said photographic material comprising a reduction-sensitized silver halide emulsion containing at least one compound represented by formula (I): ##STR22## wherein Het represents a group adsorptive to silver halide grains selected from the group consisting of:

(1) a 5-, 6- or 7-membered heterocyclic ring having 2 or more hetero atoms,

(2) a 5-, 6- or 7-membered nitrogen-containing heterocyclic ring having a quaternary nitrogen atom, which is represented by formula (A): ##STR23## (3) a 5-, 6- or 7-membered nitrogen-containing heterocyclic ring having a thioxo group, which is represented by formula (B): ##STR24## (4) a 5-, 6- or 7-membered nitrogen-containing heterocyclic ring represented by formula (C): ##STR25## and (5) a 5-, 6- or 7-membered nitrogen-containing heterocyclic ring represented by formula (D) or (E), ##STR26## wherein Za represents an atomic group necessary to form a 5-, 6- or 7-membered nitrogen-containing heterocyclic ring; Ra represents an aliphatic group; La and Lb each represent a methine group; and n represents 0, 1 or 2, provided that Her is substituted with at least one --(Q).sub.k2 --(Hy) moiety; Q represents a divalent linking group comprising an atom selected from the group consisting of a carbon atom, a nitrogen atom, a sulfur atom and an oxygen atom or an atomic group containing at least one atom selected from the group consisting of a carbon atom, a nitrogen atom, a sulfur atom, and an oxygen atom; Hy represents a hydrazine structure represented by formula (II): ##STR27## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represent an aliphatic group, an aryl group or a heterocyclic group; R.sub.1 and R.sub.2, R.sub.3 and R.sub.4, R.sub.1 and R.sub.3, or R.sub.2 and R.sub.4 may be connected to each other to form a ring, provided that at least one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 represents a divalent aliphatic, aryl or heterocyclic group to which the --(Q).sub.k2 --(Het).sub.k1 moiety is bonded;

k1 and k3 each represent 1, 2, 3 or 4; and k2 represents 0 or 1.

2. A silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion is a gold-chalcogen sensitized emulsion.

3. A silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion is a spectrally sensitized emulsion.

4. A silver halide photographic material as claimed in claim 2, wherein said silver halide emulsion is a spectrally sensitized emulsion.

5. A silver halide photographic material as claimed in claim 1, wherein said compound represented by formula (I) is selected from compounds represented by one of formulae (XI) to (XV): ##STR28## wherein Qa has the same meaning a Q; Zb represents an alkylene group having 4 to 6 carbon atoms; R.sub.42 represents an aliphatic group, an aryl group or a heterocyclic group; R.sub.43 and R.sub.44 each represent a hydrogen atom or a monovalent substituent; p2 represents an integer of 0 or more; X.sub.1 represents a hydrogen atom, an alkali metal atom, an ammonium group or a precursor thereof; R.sub.26 represents an aliphatic group; n2 represents 0 or 1; n3 represents an integer of 1 to 6; where n3 is 2 or more, the C(R.sub.43)(R.sub.44) groups do not need to be the same; R.sub.24 ' and R.sub.25 ' each represent an alkylene group, an arylene group or a divalent heterocyclic group; and R.sub.27 ' represents an alkylene group.

6. A silver halide photographic material as claimed in claim 1, wherein said compound represented by formula (I) is selected from a compound represented by formula (XVI): ##STR29## wherein Qa has the same meaning as Q; Zb represents a substituted or unsubstituted alkylene group having 4 to 6 carbon atoms, provided that the carbon atom directly bonded to the nitrogen atom of the hydrazine structure is not substituted with an oxo group; R.sub.41 represents a monovalent substituent; R.sub.42 represents an aliphatic group, an aryl group or a heterocyclic group; R.sub.43 and R.sub.44 each independently represent a hydrogen atom or a monovalent substituent; n1 represents 0 or an integer of 1 to 4; n2 represents 0 or 1; and n3 represents an integer of 1 to 6; where n1 or n3 is 2 or more, the R.sub.41 or C(R.sub.43)(R.sub.44) groups do not need to be the same.